Energy efficiency, Renewable Energy Sources, Energy Storage/Batteries, Hydrogen, Efficient Buildings, climate neutrality, reduction of greenhouse gas emissions and decarbonization of industries & coal regions are in the heart of European Policies for the new programming period (ie. Green Deal, EU Strategic Energy Technology Plan, Twin Industrial Transition etc.). Many financial instruments have been setup to support these objectives that have a common denominator in sustainable energy. EU alliances across the value chains (ie. EBA), IPCEIs (ie. Descarbonization & Hydrogen, Batteries) and Research & Policy Platforms (ie. Coal Regions in Transition), are dedicated to facilitate the advancement of R&I in the field through the collective effort of EU members, and enable the transformation of EU regions to climate neutral, thriving economies. This context finds a lot of countries striving to comply, especially challenging those that traditionally have economies heavily dependent on fossil fuel mining and exploitation; a major shift has to be done in a short amount of time, putting at risk the balances in the local economies and making years-long expertise and well-established skills become obsolete. COALition intends to strengthen the regional innovation ecosystems in coal-depended areas through the creation of regional excellence hubs and the definition of a joint strategic agenda for sustainable energy so as to facilitate their transition in a just and inclusive way. The regions have been carefully selected (Western Macedonia - GR, Centru - RO, Southeastern - BG) among the under transition EU states that are also characterized as widening, in an attempt to maximize the long-term impact of the joint R&I strategy that will be developed within the project, as those territories are about to amass large amounts of funding and COALition aims to create multiplier effects in the given investments by attracting and mobilizing external investments.